cpufreq: interactive: delete timers for GOV_START

Make sure that timers cpu_timer and cpu_slack_timer
deactivated before addition of new.

Signed-off-by: Shridhar Rasal <srasal@nvidia.com>
Signed-off-by: Bharat Nihalani <bnihalani@nvidia.com>
Git-commit: b430123367e78a6557bac3cf1558bcb85193fb12
Git-repo: https://android.googlesource.com/kernel/common/
[mattw@codeaurora.org: resolved trivial context conflict]
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>

Change-Id: If31c4049606871df6f00efdc24b1d713c86a6f69